1289046640 has 80 divisors (see below), whose sum is σ = 3605483520. Its totient is φ = 418694400.

The previous prime is 1289046623. The next prime is 1289046653. The reversal of 1289046640 is 466409821.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1289046593 and 1289046602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49936 + ... + 71215.

It is an arithmetic number, because the mean of its divisors is an integer number (45068544).

Almost surely, 2^1289046640 is an apocalyptic number.

1289046640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1289046640 is an abundant number, since it is smaller than the sum of its proper divisors (2316436880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1289046640 is a wasteful number, since it uses less digits than its factorization.

1289046640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121190 (or 121184 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 1289046640 is about 35903.2956704534. The cubic root of 1289046640 is about 1088.3189979770.

The spelling of 1289046640 in words is "one billion, two hundred eighty-nine million, forty-six thousand, six hundred forty".